IMMUNOREACTIVE LH-RELEASING HORMONE IN PLASMA: MIDCYCLE ELEVATION IN WOMEN*

Abstract
Ovulation in women requires the midcycle release of luteinizing hormone (LH) from the pituitary gland. The use of a sensitive and specific radioimmunoassay for LH-releasing hormone (LH-RH)made it possible to demonstrate that the preovulatory surge of LH is associated with an increase in LH-RH levels in the peripheral plasma, probably resulting from an increased secretion of this hormone from the hypothalamus.